Horsehair Worm

You may recall the amazing video we previously posted showing multiple parasitic wasp larvae emerging from caterpillars like something out of Alien.  How about an equally startling finding- stepping on a cockroach and facing this creature crawling out of it?  Tim Smith discussed this horsehair worm in his Fresh Afield blog in July.
I have seen these adult worms swimming around the edge of creeks and ponds but wasn't aware of their other life.  Their larvae emerge from eggs and then penetrate their hosts such as crickets, grasshoppers, cockroaches or beetles.  They inhabit spaces between their host's organs, absorbing its blood and lymph borne nutrients through their skin.
After several molts, they are ready to crawl out of their host (or emerge when it is stepped on as above).  They then start a free life in a moist environment, looking for love.  When they encounter a mate, they form a tight knot together, leading to their other name, the Gordion worm.   It is doubtful that they are aware that Alexander the Great sliced through the Gordion Knot or they might try another strategy.
You might think about them the next time you think about killing a cockroach- but I doubt it will stop you.
Details are in Wikipedia.